Rotary bit



y 1941. J. w. H ATCHER, s'R 2,241,549

ROTARY BIT Filed Feb. 6, 1940 2 Sheets-Sheet 1 May 13, 1941. J. w. HATCHER, SR

ROTARY BIT Filed Feb. 6, 1940 2 Sheets-Sheet 2 Patented May 13, 1941 UNITED STATES PATENT OFFICE ROTARY BIT John W. Hatcher, Sr., Oildale, Calif.

Application February 6, 1940, Serial No. 317,601

Claims.

This invention relates to a rotary bit and more particularly to a bit used for drilling oil wells and other deep wells which are drilled through rock and other hard formations.

One object of the invention is to provide a drill wherein rotary cutters are so mounted that when the bit is turned, the cutters, which are rotatably mounted, have transverse scraping motion as well as turning motion. It will thus be seen that a very good cutting and scraping action will take place and a well bored which will be of the same diameter throughout its depth.

Another object of the invention is to provide a drill wherein there are provided sets of oppositely disposed rotary cutters, the cutters of one set extending downwardly below the plane of the other set and adapted to cut the bottom of the well hole in advance of the cutters of the other set. It will thus be seen that marginal portions of the well bottom will first be cut by one set of cutters and the remainder of the well bottom then cut by the other set of cutters and a rapid drilling action effected.

Another object of the invention is to provide the drill with a body carrying arms for rotatably supporting the rotary cutters and, in addition, provide the body of the cutter with ports, so that water, thin mud, or the like, may be directed toward the cutters in such angular relation thereto that the cutters will be kept clean and prevented from becoming clogged by cuttings and other muck in the bottom of the well.

Another object of the invention is to provide cutters having certain of their circular blades so formed that they act as spinners when struck by jets of mud or water and permit the cutters to be rapidly rotated for quick and thorough cleaning of the cutters when the cutters are held out of contact with the bottom of a well hole.

Another object of the invention is to provide a drill which is simple in construction, strong and durable, and very efiicient in operation.

The invention is illustrated in the accompanyingdrawings, wherein:

Fig. l is a side elevation of the improved drill.

Fig. 2 is a side elevation taken at right angles to Fig. 1.

Fig. 3 is a sectional view taken vertically through the drill on the line 3-3 of Fig. 5.

Fig. 4 is a vertical sectional view on the line 4-4 of Fig. 5.

Fig. 5 is a sectional view taken horizontally through the drill on the line 5-5 of Fig. 3.

Fig. 6 is a sectional view taken on the line 6-6 of Fig. 1.

This improved drill is to be applied to the lower end of a hollow drill rod or shaft l which consists of the usual tubular sections, and since each section of the drill shaft or rod has an internally threaded lower end portion, the threaded shank 2 of the drill head or body 3 may be screwed into the lower end of the drill rod, as shown in Figs. 3 and 4. The shank is hollow, but the head or body is solid and formed with a plurality of ports or passages bored through the head at an incline and diverging downwardly so that jets of water or mud will be discharged downwardly from these ports at an outward incline, as indicated by the arrows in Figs. 3 and 4.

An arm 5, form-ed integral with the body or head 3, extends downwardly therefrom in axial alinement with the head and, at its lower end, carries a cross head 6 having flat side faces flush with side faces of the arm 5. Stub shafts or axles I extend from opposite sides of the cross head 6 under the arm 5, and attention is called to the fact that these axles are out of alinement with each other and also so located that they extend from the cross head at opposite sides of the vertical axis of the arm 5 and head or body 3. Therefore, the axles l are in offset parallel relation to a line extending diametrically of the vertical axis of the head 3 and shaft I.

Heads 8 are formed integral with ends of the cross head 6 but located at opposite sides thereof so that the axles or stub shafts 9 which project from these heads are disposed at opposite sides of a line extending longitudinally through the cross head diametrically of the vertical axis of the head 3 and the shaft I. These axles extend outwardly at an upward incline, as shown in Fig. 4, instead of being horizontal as are the axles I.

Cutters l0 and II are rotatably mounted about the axles l and 9 and, in order to permit the cutters to turn freely about the axles, there have been provided roller bearings 2 and i 3. Securing members 14 are threaded upon outer ends of the axles 1 and, together with the balls 15, serve as thrust bearings for outer ends of the cutters [0. Instead of securing the cutters ll upon the axles 9 by threaded washers, there have been provided brackets 16 having collars I! at their lower ends for fitting about outer ends of the axles l. The brackets l6 extend at an incline, as shown in Figs. 2 and 4, and, at their upper ends, are formed with heads l8 which are curved transversely and fit into recesses I9 formed at opposite sides of the head or body 3 where they are secured by a suitable number of screws 20. The brackets serve to support outer ends of the axles 9 as well as serving to hold the cutters H in place thereon, and, together with the bearing balls 2|, provide thrust bearings for the outer ends of the cutters. The cutters ii! and H are formed with circumferentially extending sharpened discs or blades 22 and 23 by means of which rock and other material is cut from the bottom of a well hole, and attention is called to the fact that since the axles I are in a higher plane than the axles 9, the discs 23 of cutters H extend downwardly below the discs 22 of cutters l and operate on marginal portions of the bottom of the well hole in advance of the discs or cutters when the drill is held in elevated position a short distance above the bottom of the well hole and the blades of the discs or propellers Z'Zaand 2341 are struck by jets of water or mud discharged from the bores or passages l of the head or body 3.

When this drill is in use, it is mounted at the lower end of the drill shaft or rod I and turns therewith.- The annular blades or discs of the cutters are of sufficient hardness and sharpness to cut the rock or'other material through which the hole is to be bored and since the cutters extend out of radial relation to the axis of the shaft, the discs or circular blades do not merely move in a circular path but also have movement transversely of the axles while turning thereon and have dragging or scraping engagement with I the bottom of the well hole. A very good scraping and cutting action will thus take place as the drill shaft and drill turn about the vertical axis of the drill shaft. Since the cutters ll extend downwardly below the plane of the cutters In, a

they will act on marginal portions of the bottom of the well hole in advance of the cutters l0 and the marginal portions of the bottom of the hole will first be cut and then the remainder of the cutting take place. This reduces frictional drag on the cutters and permits the cutting to be easily done and a hole rapidly bored. As the cutters are conical, frictional resistance will be further reduced. Since the water or mud used as a drilling fluid is forced downwardly through the hollow drill shaft and out through the bores or ports 4 as high speed jets, these jets will strike the cutter with sufficient force to dislodge muck therefrom. The directions in which the ports are cut causes the jets to strike the cutters transversely of their circular blades and easily remove muck therefrom. If it is found that the cutters have become somewhat clogged, the drill may be drawn upwardly a short distance and contact of the jets with the blades of the discs 2 2a and 23a, which serve as spinners or propellers, will cause the cutters to turn very rapidly and accumulated muck will be thrown off lay-centrifugal force as well as being washed from the cutters by the Washing action of the drilling fluid.

Having thus described the invention, what is claimed is:

1. In a drill of the character described, a head adapted to be carried by a drill rod, an arm extending downwardly from said'head, a cross head at the lower end of said arm, brackets carried by said head andextending downwardly from opposite sides thereof and provided withcollars at their lower ends, axles extending from opposite sides of the cross head out of 'alinement with each other, other axles extending from opposite ends of the cross head out of alinement with each other and disposed at an upward incline with their outer end engaged through said collars, cutters rotatably mounted about said axles and having circumferelntially extending cutting disks, means at the outer ends of the first mentioned axles for holding the cutters thereon, and said body being formed with passages over the cutters for discharge of drilling fluid downwardly onto the cutters.

2. In a drill of the character described, a head adapted to be mounted at the lower end of a drill rod, members extending downwardly from said head, axles carried by said members and extending laterally of the head in transverse spaced re lation to diametrical planes of the head, certain ofsaid axles extending horizontally and the others at an upward incline towards their outer ends, cutters rotatable about said axles havin circumferentially extending blades, the cutters carried by certain of said axles extending downwardly below the plane of the lower edges of the lades of the other cutters, and said head being formed with bores for discharging drilling fluid downwardly against the cutters and dislodging muck from blades thereof.

3. In a drill of the character described, a head adapted to be mounted at the lower end of a drill rod, mounting members extending downwardly from said head, axles carried by said mounting members and extending laterally of the head, said axlesbeing located in spaced and substantially parallel relation to common diametrical planes of the head, and cutters rotatably mounted about said axles and having circumierentially extending blades, certain of said axles extending horizontally and the others at an upward incline toward their outer ends, and the cutters carried by the inclined axles extending downwardly below the plane of the lower' edges of the blades of the other cutters for engagement with portions of the bottom of a well hole in advance of the bottom of the well hole engaged by the other cutters.

4. In a drill of the character described, a head adapted to be mounted at the lower end of a drill rod, mounting member extending downwardly from said head, axles carried by said mounting members and extending laterally of the head, said axles being located in spaced and substantially parallel relation to diametrical planes of the head, and cutters rotatably mounted about said axles and having rotary motion and transverse scraping engagement with the bottom of a well hole when the drill and a drill shaft carrying the same are turned in a well hole, said cutters each having a plurality of annular blades progressively decreasing in diameter towards its inner end.

5. A drill of the character described including a body adapted for connection with the lower end of .a drill rod, and rotatably mounted cutters located under the body laterally thereof, said cutters having circumferentially extending blades, one blade of each cutter being formed of circumferentially extending segmental adapting the same to act as a spinner, and said body being formed with bores for discharging drilling fluid downwardly against the cutters for dislodging material from the blades and acting on the spinners for rapidly rotating the cutters when the cutters are out of contact with the bottombf a well hole.

JOHN W. HATCHER, sa.

sections 

